The most widely used public data network in the United States and the world at large is the network commonly known as the Internet. The Internet had its genesis in U.S. Government (called ARPA) funded research which made possible national internetworked communication systems. This work resulted in the development of network standards as well as a set of conventions for interconnecting networks and routing information. These protocols are commonly referred to as Transmission Control Protocol/Internet Protocol (TCP/IP). The protocols generally referred to as TCP/IP were originally developed for use only through Arpanet and have subsequently become widely used in the industry. TCP/IP is flexible and robust; in effect, TCP takes care of the integrity and IP moves the data. Internet provides two broad types of services: connectionless packet delivery service and reliable stream transport service.
The Internet basically comprises several large computer networks joined together over high-speed data links ranging from ISDN to T1, T3, FDDI, SONET, SMDS, OC1, etc. The most prominent of these national nets are MILNET (Military Network), NSFNET (National Science Foundation NETwork), and CREN (Corporation for Research and Educational Networking). The U.S. government's 1991 decision to end subsidizing the NSFNET backbone beginning in 1995 resulted in massive restructuring directed to shaping the Internet into a productive tool for business. In 1995, the Government Accounting Office (GAO) reported that the Internet linked 59,000 networks, 2.2 million computers and 15 million users in 92 countries. It is presently estimated that the growth of the Internet is at a more or less annual doubling rate.
Generally speaking the Internet consists of Autonomous Systems (AS) which may be owned and operated by Internet Service Providers (ISPs) such as PSI, UUNET, MCI, SPRINT, etc. The Autonomous Systems (ASs) are linked by Inter-AS Connections. Information Providers (IPs), such as America Online (AOL) and Compuserve, are connected to the Internet via high speed lines, such as T1/T3 and the like, and generally do not have their own Internet based Autonomous Systems but have or use Dial-Up Networks such as SprintNet (X.25), DATAPAC and TYMNET. By way of current illustration MCI is both an ISP and an IP, Sprint is an ISP, and MicroSoft (MSN) is an IP using UUNET as an ISP. Other information providers, such as universities, are connected to the AS/ISPs via the same type connections. Corporate Local Area Networks (LANs) are connected through routers and links such as T1 lines. Personal computers (PCs) and Laptop computers are representative of computers connected to the Internet via the public switched telephone network (PSTN) and AS/ISPs via dial up links.
The Information Providers (IPs) constitute the end systems which collect and market the information through their own servers. Access providers are companies such as UUNET, PSI, MCI and SPRINT which transport the information. Such companies market the usage of their networks.
Commercial ISPs may range in size from commonly called "mom and pop operations" to national entities offering connectivity services nationwide or internationally in some instances. An increasing number of such national ISPs have begun to offer proprietary services in addition to simple Internet access. Examples of these ISPs are presently America on Line (AOL), CompuServe, and Prodigy. FIG. 1 shows a typical architecture of such an Internet Service Provider (ISP) which offers proprietary content services.
Aggressive competition by regional ISPs has recently induced a number of the larger national ISPs to offer flat-rate pricing coupled with intensive advertising. This has been received with enthusiasm with the result that leading systems are frequently overloaded. More and more users are buying computers which are sufficiently powerful to send video and photographs, which constitute data-intensive material that can clog lines. In addition, more and more companies are using the Internet to conduct their business, communicate with and support their customers, exchange electronic mail with hundreds of thousands of users, seek and find valuable information. The most common forms of the overload are twofold. Customers frequently encounter busy signals due to lack of line capacity following the dialing of a hunt-group type directory number. This produces a complete inability for the customer to connect to the ISP. Secondly, there is frequent overload in one or more of the modem pool, host or server, and/or router of the ISP. These types of overload result in both inability to reach the ISP server, as well as sluggish operation of the system with frequent and sometimes extensive delays after the customer is on-line.
One approach to the overload problem has been proposed in U.S. application Ser. No. 08/816,229 cited above, and assigned to the assignee of the instant application. According to that proposal the capabilities of an Advanced Intelligent Network (AIN) associated with a transporting telephone company (TELCO) are utilized to effect simultaneous multiple line redirection in accord with predetermined conditions established by the ISP. By way of example, the ISP may know that load peaks at known times of day and days of the week. The ISP accordingly pre-designates a series of lines in one or more hunt groups to be redirected to additional lines, servers and routers automatically when the pre-determined conditions exist. In this manner incoming calls during the peak hours are handled by automatically increasing the number of lines, servers, and routers to which those calls are directed. The additional lines, servers, and routers may direct the calls through facilities of the telephone company or of a competitive ISP. Although this solution entails the additional expense of at least temporarily using TELCO or a competitor's facilities, it provides the expanding ISP the significant advantage of permitting it to continue to acquire customers as it enlarges its own facilities, if it so chooses.
While the foregoing innovation provides a significant step towards facilitating the handling of ever-increasing Internet traffic, it does not address the problem presented by unforeseeable rapid increases in load as they may dynamically occur.